Lauren Mason – Page 22

Charging-driven coarsening and melting of a colloidal nanoparticle monolayer at an ionic-liquid vacuum interface

Colloidal materials are a platform for studying self-assembly as well as the bottom-up creation of next generation hierarchical materials, and controllably perturbing their collective dynamics is an important step towards directing their assembly. In a liquid droplet, silica nanoparticles collect on the surface and organize to form an ordered 2D lattice. A STROBE research team led by Naomi Ginsberg (UC Berkeley) investigated these monolayers on a low vapor pressure ionic liquid, allowing experiments to be performed under the vacuum environment of a scanning electron microscope. Alongside imaging the particles, the electron beam serves as a perturbative tool for controllably charging the colloidal lattice. As particles charge, they sink into the droplet reducing the monolayer’s density and driving a melting transition. These findings will provide new insights for understanding phase transitions in soft materials and analogous atomic crystals.

Computer Vision for Imaging

This talk will discuss examples of computer vision algorithms applied to XRT, XRD and optical microscopy; it will also illustrate image transformations using Jupyter notebooks. Dani Ushizima PhD, is a Staff Scientist at Lawrence Berkeley National Laboratory, a Data Scientist at UC Berkeley and an Affiliate Faculty at UC San Francisco. In 2015, Ushizima received the U.S. Department of Energy Early Career award to focus on pattern recognition applied to diverse scientific domains, such as structural analysis of materials science samples. She is also recipient of the Science without Borders Researcher award (CNPq/Brazil) for her work on machine learning applied to cytology, as part of an initiative focused on public healthcare. She has also led the Image Processing team for the Center for Advanced Mathematics for Energy Related Applications (CAMERA). Recently, she’s been investigating lung scans for COVID-19 screening as part of initiatives related to the National Virtual Biotechnology Laboratory (NVBL).

“Determining Atomic Structures from Digitally Defined Regions of Nanocrystals” and “High resolution imaging through scattering media”

Determining Atomic Structures from Digitally Defined Regions of Nanocrystals

Presented by Marcus Gallagher-Jones, postdoc, Jose Rodriguez group, UCLA

Abstract:

The ability of molecules to form ordered assemblies is a crucial first step in preparing samples for structural characterization with atomic-level detail. For many complex molecules, the length scales to which this order extends is limited, thus hampering efforts to solve their structures. In our current work we attempt to overcome these challenges by extending recent developments in 4D-STEM. By combining 4D-STEM data collection with tomography we demonstrate that atomic structures of macromolecules can be solved from specific regions of polymer nanocrystals. In this method, scanning nanobeam electron diffraction tomography (nanoEDT), peptide nanocrystals are rotated about a tilt axis in one-degree steps. At each tilt angle a direct electron detector captures thousands of sparse diffraction patterns mapped to specific locations within a single crystal. The use of direct electron detection, in combination with data collection at cryogenic temperatures and a hybrid counting algorithm, allows even weak signals from high-resolution Bragg peaks to be accurately recorded from radiation sensitive crystals. NanoEDT breaks new ground in nanocrystallography by allowing atomic structures to be determined from any region of a nanocrystal through the use of virtual, selected-area apertures, potentially leading to the determination of atomic structures from heterogeneous or polycrystalline nanoassemblies.

High resolution imaging through scattering media

Presented by Sakshi Singh & Evolene Premillieu, graduate students, Rafael Piestun group, CU Boulder

Abstract:

Imaging through scattering media is a critical area with impact in biological and biomedical research. While most current research focuses on achieving the highest possible resolution, in practice, scattering is often the main limitation. Scattering diffuses light, leading to a reduction in contrast and signal-to-noise ratio, which makes imaging impractical. The implications of this study span all imaging modalities from visible light to electron beam. One approach to deal with scattering involves characterizing the medium by measuring its transmission Matrix (TM). Once the TM is acquired, imaging and focusing inside the medium become feasible. Here we present two critical advances in this field. The first involves TM measurement using fluorescence (namely incoherent light) as feedback, allowing to focus light on an extended field of view behind a scatterer. Secondly, we demonstrate a huge step up in the imaging speed with the help of a grating light valve (GLV) that enables rapid and continuous focusing through scattering media at a record speed.

What to Know if You’re Teaching Physics Labs Remotely

The coronavirus pandemic upended schools in the spring of 2020, sending students and faculty home. This rapidly changed how instructors handled laboratory physics courses. With a NSF RAPID grant, JILA Fellow Heather Lewandowski asked instructors what worked—and what didn’t—as they moved their lab courses online.

New electron microscope at CU Boulder enables groundbreaking research across disciplines—and from a distance

Capable of achieving spatial resolutions of 70 pm—smaller than the size of an atom—the Thermo Scientific Titan Themis S/TEM, located in the newly-launched CU Facility for Electron Microscopy of Materials (CU FEMM), is now the highest-resolution electron microscope in Colorado.

Taller than a person and equipped with multiple cameras and detectors, this state-of-the-art, aberration-corrected electron microscopy platform makes groundbreaking research possible in a wide range of fields, including catalysis, advanced imaging, quantum information, energy conversion, biomaterials, battery research, geology, materials development and even archaeology. A team from the National Center for Atmospheric Research (NCAR) is even exploring a potential COVID-19 study using the microscope to inspect the salt from dried saliva droplets.

Congrats to Sakshi Singh for Being Selected as a Winner of the 2020 Colorado Photonics Industry Association (CPIA) Poster Contest

Congratulations to Sakshi Singh for Being Selected as a Winner of the 2020 Colorado Photonics Industry Association (CPIA) Poster Contest. Sakshi’s poster is titled, “Robust, fast, and high-resolution ultra-thin fiber endoscopes.“

Congrats to Yuka Esashi for Being Selected as a Winner of the 2020 Colorado Photonics Industry Association (CPIA) Poster Contest

Congratulations to Yuka Esashi for Being Selected as a Winner of the 2020 Colorado Photonics Industry Association (CPIA) Poster Contest. Yuka’s poster title is, “Phase-Sensitive EUV Imaging Reflectometer for Depth-Dependent Composition Determination.”

Congrats to Jose Rodriguez for Being Recognized as One of the Most Inspiring Hispanic/Latinx Scientists in the United States by Cell Press

In honor of National Hispanic Heritage Month, we’re showcasing 100 of the most inspiring Hispanic/Latinx scientists working in the United States. This list—selected based on scholarly achievements, mentoring excellence, and commitment to diversity, equity, and inclusion—represents only a subset of the scientific role models in the community. Our aim in assembling these names is to put an end to the harmful myth that there are not enough diverse scientists to give seminars, serve as panelists, or fill scientific positions. We highlight scientists encompassing careers within academia, government, and biotech and showcase individuals committed to serving diverse student populations at Hispanic-serving institutions. Although we understand this list is not fully representative of the Hispanic/Latinx scientific community, we hope it will help to change the perception of what a scientist looks like and makes our collective image more representative of society at large.

World’s Smallest ‘Refrigerator’

Thermoelectric devices represent a potentially transformative technology, one that could revolutionize power generation and temperature control. While they are robust, compact, noiseless, and have no moving parts, thermoelectric devices are implemented only in a few niche applications because of their low efficiency compared to conventional, compression-based heat engines. According to well-grounded theoretical considerations, thermoelectric materials might be made more efficient than their bulk counterparts via tailored nanostructuring. Given the large upside, even small improvements in thermoelectric materials might bring us to a tipping point where thermoelectric devices are routinely employed for recovering waste heat and refrigerating food.

A STROBE team led by Chris Regan (UCLA) has developed new imaging techniques for characterizing thermoelectric devices at the nanoscale, and has demonstrated these techniques on the smallest refrigerator ever constructed. Their thermoelectric refrigerator has an active volume of about 1 cubic micrometer, which is too small to be seen with the naked eye. Viewed in a microscope, it demonstrates its cooling abilities by forming a single dewdrop instantaneously when electrical power is applied. This work is continuing in collaboration with researchers at the STROBE/PEAQS partner institutions Fort Lewis College and Norfolk State University.

University of Colorado Boulder: Tenure Track Openings in the College of Engineering and Applied Sciences

University of Colorado Boulder: Tenure Track Openings in the College of Engineering and Applied Sciences

For the 2020-2021 search cycle, the College of Engineering and Applied Science at the University of Colorado Boulder is conducting two tenure track searches.

1) Multiple Open-Discipline Faculty Positions in Engineering and Applied Science

As part of our commitment to creating a diverse, equitable, and inclusive academic culture in the College of Engineering and Applied Science (CEAS) at the University of Colorado Boulder, we are launching a new college-wide search for multiple tenured/tenure track faculty positions rostered among any/all of the six departments and six interdisciplinary programs in the college. We anticipate hiring at the assistant and associate professor levels, although qualified candidates will be considered at the full professor rank.

This search is motivated by the four core values of the college’s strategic vision: accelerate our research impact to produce advances in technology and benefits to society, embrace our public education mission including expanding access and participation of diverse and underrepresented communities in engineering and computer science, increase our global engagement, and enrich our professional environment.

https://jobs.colorado.edu/jobs/JobDetail/?jobId=26989

2) Faculty Position in Electrical, Computer & Energy Engineering

The Department of Electrical, Computer & Energy Engineering at the University of Colorado Boulder seeks well-qualified candidates for a Tenure-Track Faculty position in the areas of machine learning (distributed, explainable, secure, etc.), signal processing (statistical, sparse, distributed, high-dimensional data, etc.), network science, and/or information/communication theory (5G and beyond). Such candidates would have demonstrated, or potential for future, excellence in research in the theory, algorithms, and emerging applications of these disciplines. Synergistic and interdisciplinary research that cuts across them is a plus. Excellent candidates at the early Associate professor level with tenure will also be considered.

https://jobs.colorado.edu/jobs/JobDetail/?jobId=27067

The University of Colorado Boulder is committed to building a culturally diverse community of faculty, staff, and students dedicated to contributing to an inclusive campus environment. We are an Equal Opportunity employer, including veterans and individuals with disabilities.

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About Lauren Mason